Improvement in electro-magnets



Lamm.

Improvement in Electro-Magnets.

N0. 125,151. Patented April2,1872.

UNITED STATES PATENT OEEIGE.

ISAAC P. TICE, OF NEW YORK, N. Y.

IMPROVEMENT IN ELECTRO-MAGNETS.

Specification forming part of Letters Patent No. 125,151, dated April 2, 1872; antedated March 15, 1872.

To all ywhom it may concern:

Beit known that I, ISAAC l). TICE, of the city, county, and State of New York, have invented a new and useful Improvement in Electro-Magnets, and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the aecompanyin g drawing forming part of this specification, and which represents a partly sectional view of an electro-magnet constructed in accordance with my invention.

Uy invention consists in a com pound electromagnet, having its limbs surrounded by helices of unequal size or length, wound in opposite directions upon each of its limbs, so that, accordingly as the current of electricity, with which the magnet is charged, is changed from one pair of helices to another, the magnetic polarity ofthe limbs is reversed, and the whole mass of the limbs vertically demagnetized.

To make clear the object of the invention, a brief reference will here be made to a wellknown fact, which is this: when an electromagnet of ordinary construction has been energized by the passing of a current of electricity around its limbs, it continues to attract the armature it serves to control for a longer or shorter period after the current has been cutoff from it. To release the armature as rapidly as it was attracted or brought in contact, the magnet must be demagnetized as quickly as it was energized, or else considerable mechanical force must be applied to separate the armature from the limbs. Supposing said magnet to be the controlling or operating device of an electro-magnetic engine, then just so much power as is required to detach the armature from the limbs of the magnet is absorbed in the working of the engine, or, in other words, is lost so far as the effective power ot' the engine is concerned.

My invention entirely overcomes this difficulty, as will be explained by reference to the magnet represented in the accompanying drawing, and keeping in view the following well-known laws or rules as applied to a horseshoe-magnet, namely, that if a current of positive electricity enter a right-handed helix,

the limb inclosed by said helix forms a south magnetic pole, or a north magnetic pole if said helix be reversed; likewise that like poles repel and opposite poles attract.

A B in the drawing' represent the two cores or limbs of the magnet; and c c are the working ends of an insulated wire joined at and wound, preferably only once, around the cores in a left-handed direction, the same forming left-handed helices C O. Outside of these helices is wound repeatedly, so as to form a series of coils, having a right-handed direction, another wire, joined as at y, the same constituting right-handed helices D D, of which d df are the Working ends, and which, by their enlarged proportion, relatively to the left-handed helices C O, serve to give the required lift to the magnet, or, in other words, are the operating helices of the magnet 5 while the inner or smaller helices G O are or may be proportioned simply to effect the change of polarity and to neutralize the magnetic force remaining in the limbs after the current has been eut ofi' from entry through the right-handed and larger helices D D.

If a current of positive electricity be made to pass through the right-handed helices D D, then the south pole will be at A, and the opposite limb B will be the north pole. Supposing, however, this current to be cut oif, or rather to be changed so as to pass through the left-handed helices O O, then B becomes the south pole, and A the north one. This amounts practically to changing the twist ofthe wires which convey the current around the cores, and so reverses the poles, and at the moment of reversal produces complete demagnetiza tion, as it were. Such action, also, by the neutralizing eii'ect of the current passing through the helices O G, prevents the magnet from becoming a permanent onethat is, from exerting a permanent attraction instead of attracting with its full power only at intervals, as required.

I do not confine myself to the precise manner here shown of winding and arranging the helices, for it is obvious that the inner or re versing helices might be wound below the other or operating helices, and independent of What is here claimed, and desired to be sethe latter, either `upon the same or separa-te cured by Letters Patent, is-

cores; but -in -the latter case longer helices A compound electro-magnet havingits limbs would be required, and the cost of construcsurrounded byhelices ofunequal size orlength,

tion would be increased. Wound in opposite directions upon each ot' its By a combination of reverse helices, as delimbs, substantially as and for the purpose or scribed, the induced currents of electricity are purposes herein set forth.

regulated and neutralized7 and are 11o longer Witnesses? ISAAC P. TICE. an obstacle to the rapid powerful action of an M. M. LEGGETT, electro-magnet. ISAAC D. SAILER. i 

